Description
PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| jpadilla | pyjwt | < 2.13.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pyjwt | 2.13.0-1 | — |
| Debian 13 | pyjwt | No fix yet | — |
| Debian 12 | pyjwt | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | pyjwt | 2.10.1-4ubuntu1.1 | USN-8823-1 |
| Ubuntu 25.10 | pyjwt | No fix yet | — |
| Ubuntu 24.04 LTS | pyjwt | 2.7.0-1ubuntu0.2 | USN-8823-1 |
| Ubuntu 22.04 LTS | pyjwt | 2.3.0-1ubuntu0.4 | USN-8823-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | pyjwt | 1.7.1-2ubuntu2.1+esm2 | USN-8823-1 |
| Ubuntu Pro 18.04 LTS | pyjwt | 1.5.3+ds1-1ubuntu0.1+esm2 | USN-8823-1 |
| Ubuntu Pro 16.04 LTS | pyjwt | 1.3.0-1ubuntu0.1+esm2 | USN-8823-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES 15 SP5 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES 15 SP4 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES 3 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-PyJWT | 2.12.1-160000.2.1 | SUSE-SU-2026:22170-1 |
| SLES for SAP 15 SP6 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES for SAP 15 SP5 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES for SAP 15 SP4 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLES 16.0 | python-PyJWT | 2.12.1-160000.2.1 | SUSE-SU-2026:22170-1 |
| SLE Micro 6.2 | python-PyJWT | 2.12.1-160000.2.1 | SUSE-SU-2026:22220-1 |
| SLE Micro 6.1 | python-PyJWT | 2.12.1-slfo.1.1_2.1 | SUSE-SU-2026:22138-1 |
| SLE Micro 6.0 | python-PyJWT | 2.9.0-3.1 | SUSE-SU-2026:22238-1 |
| SLE HPC 15 SP5 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
| SLE HPC 15 SP4 | python-PyJWT | 2.8.0-150400.8.13.1 | SUSE-SU-2026:2626-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-PyJWT | 2.13.0-1.1 | openSUSE-SU-2026:11024-1 |
| openSUSE Leap 16.0 | python-PyJWT | 2.12.1-160000.2.1 | openSUSE-SU-2026:21095-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-jwt | 2.13.0-1 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | datadog-agent-7.72-core-integrations | No fix yet | — |
| Wolfi rolling | datadog-agent-7.73-core-integrations | 7.73.3-r23 | — |
| Wolfi rolling | datadog-agent-7.77-core-integrations | 7.77.3-r16 | — |
| Wolfi rolling | datadog-agent-7.78-core-integrations | 7.78.4-r10 | — |
| Wolfi rolling | datadog-agent-7.79-core-integrations | 7.79.2-r6 | — |
| Wolfi rolling | datadog-agent-7.80-core-integrations | 7.80.4-r3 | — |
| Wolfi rolling | ggshield | 1.52.2-r1 | — |
| Wolfi rolling | kserve +1 | 0.20.0-r7 | — |
| Wolfi rolling | kserve-storage-controller | 0.19.0-r2 | — |
| Wolfi rolling | superset-6.0 | 6.0.0-r17 | — |
| Wolfi rolling | superset-6.1 | 6.1.0-r2 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | pyjwt | >= 2.0.0, < 2.13.0 | 2.13.0 | GHSA-fhv5-28vv-h8m8 |
| PyPI | pyjwt | < 2.13.0 | 2.13.0 | PYSEC-2026-177 |
Advisories 8
- USN-8823-1 pyjwt vulnerabilities Ubuntu Security Notices (USN) · Sep 28, 2026
- openSUSE-SU-2026:21095-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:22238-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 26, 2026
- SUSE-SU-2026:2626-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 26, 2026
- SUSE-SU-2026:22220-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:22170-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:22138-1 Security update for python-PyJWT SUSE / openSUSE Security Updates · Jun 18, 2026
- openSUSE-SU-2026:11024-1 python311-PyJWT-2.13.0-1.1 on GA media SUSE / openSUSE Security Updates · Jun 14, 2026